Polyurethane foamed soundproofing material for indoor floor, preparation method and application

Abstract

The application discloses an indoor floor polyurethane foaming sound insulation material, a preparation method and application, and belongs to the technical field of building materials. The material is prepared by the reaction foaming of A component and B component. The A component comprises a ternary polyether polyol composition, a composite assistant crosslinking agent, a composite foaming agent, a core-shell structure damping sound insulation modifier with high-strength hollow glass microbeads as a core and butyl rubber as a shell, a composite catalyst and a foam stabilizer in a specific ratio. The B component is an isocyanate prepolymer modified by a hydroxyl-terminated polybutadiene. The polyurethane foaming material with high closed cell rate, low thermal conductivity, excellent compression performance and outstanding low-frequency impact sound insulation performance (L'nT, w≤64 dB) is obtained through the compounding and synergy of functional raw materials, the thermal conductivity is ≤0.035 W / (m·K), the compression performance is ≥300 kPa, the sound insulation, heat preservation, bearing and environmental protection are perfectly balanced, and the material is particularly suitable for the sound insulation and heat preservation system of an indoor floating floor.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a polyurethane foam sound insulation material for indoor floors, its preparation method, and its application. Background Technology

[0002] With the increasing standards of green building and the growing demand for acoustic comfort in living environments, the problem of impact sound insulation in building floors is becoming increasingly prominent. Impact sounds (such as footsteps and falling objects) mainly propagate through structural solids, attenuate slowly, and cause significant disturbance to downstairs residents. Laying an elastic padding layer between the floor surface layer and the structural layer to form a "floating floor" is an effective way to solve the problem of impact sound transmission. Polyurethane foam has potential applications in this field due to its advantages such as on-site foaming, seamless construction, lightweight, and good thermal insulation.

[0003] There are already some related studies in the existing technology, such as: CN201611142163.9 discloses a sprayed polyurethane semi-rigid foam with sound insulation effect.

[0004] CN202311004442.9 discloses a sound-insulating coating containing a variety of organic sound-insulating fillers.

[0005] CN202311116092.5 discloses a halloysite nanotube modified polyurethane elastomer sound insulation material.

[0006] However, existing technical solutions often have the following shortcomings when dealing with the specific scenario of indoor floors: (1) The sound insulation performance, especially the insulation effect against low-frequency impact noise, is insufficient and it is difficult to consistently meet the strict requirements of ≤65dB for three-star green building in the "Green Building Evaluation Standard" (GB / T50378-2019).

[0007] (2) It is difficult to simultaneously achieve excellent elastic sound insulation performance and sufficient compression performance. When used on the ground, it is prone to long-term compression creep or collapse, resulting in poor durability.

[0008] (3) It is difficult to meet the comprehensive green building indicators of "high sound insulation, low thermal conductivity and low VOC" in a coordinated manner. Some materials have foaming agents that are not environmentally friendly or have excessive VOC release. Summary of the Invention

[0009] This invention provides a polyurethane foam sound insulation material for indoor floors, its preparation method, and its application. The polyurethane foam sound insulation material (particularly suitable for indoor floating floor slab designs) simultaneously achieves excellent low-frequency sound insulation, high-efficiency thermal insulation, high compressibility, and environmentally friendly properties.

[0010] To solve the above problems, the present invention is achieved through the following technical solution: The first objective of this invention is: A polyurethane foam sound insulation material for indoor floors is provided, which is prepared by reacting and foaming component A and component B at a mass ratio of 1:1 to 1.5. Component A comprises the following raw material components in parts by weight: 100 parts of polyether polyol composition, 1-5 parts of crosslinking agent, 2-6 parts of composite foaming agent, 5-20 parts of damping and sound insulation modifier, 0.1-2 parts of composite catalyst, and 1-3 parts of foam stabilizer. The polyether polyol composition is a ternary compound system composed of high-functionality rigid polyether polyol, long-chain flexible polyether polyol, and bio-based polyether polyol in a mass ratio of 2-3:3-4:2-3; wherein... The high-functionality rigid polyether polyol has a functionality of 6-8 and a hydroxyl value of 350-450 mgKOH / g, providing high crosslinking density and a rigid skeleton to ensure compression performance and solve the problem of ground collapse under foot traffic. The long-chain flexible polyether polyol has a functionality of 2-3 and a hydroxyl value of 50-100 mgKOH / g. The molecular chain introduces a large number of flexible ether segments, which improves the damping performance of the material and enhances the attenuation of low-frequency impact sound. The bio-based polyether polyol is castor oil-based or soybean oil-based polyether polyol with a functionality of 2-3 and a hydroxyl value of 100-200 mgKOH / g, which helps to reduce VOCs, enhance compatibility with fillers, and meet environmental protection requirements. The damping and sound insulation modifier is a core-shell structured powder with high-strength hollow glass microspheres as the core and cross-linked butyl rubber as the shell; in the core-shell structure, the mass ratio of the core material to the shell material is 7:3 to 6:4, and the thickness of the shell layer is 8μm to 15μm. Component B is a hydroxyl-terminated polybutadiene-modified polymethylene polyphenyl isocyanate prepolymer with an NCO content of 28-32%.

[0011] By introducing flexible long chains of hydroxyl-terminated polybutadiene (HTPB, molecular weight 1000-2000) through prepolymerization, a microphase separation structure is formed in the hard segment of polyurethane, which significantly improves the internal damping and sound insulation performance of the material and precisely optimizes the attenuation of impact sound.

[0012] A further optimization of the polyurethane foam sound insulation material for indoor floors described in this invention is as follows: The crosslinking agent is a composite system composed of trimethylolpropane and bisphenol A dihydroxyethyl ether in a mass ratio of 0.5-1:1-2.

[0013] Bisphenol A dihydroxyethyl ether contains rigid benzene rings and flexible ether bonds, combining the dual functions of cross-linking chain extension and reinforcement with damping and sound insulation; the benzene ring structure can improve the material's heat resistance and dimensional stability, preventing thermal expansion and contraction deformation of the ground during long-term use.

[0014] A further optimization of the polyurethane foam sound insulation material for indoor floors described in this invention is as follows: The composite foaming agent is a composite system composed of deionized water and HFO-1234ze in a mass ratio of 1:3 to 5, which enables precise control of the foam structure.

[0015] By using deionized water (a chemical foaming agent) and HFO-1234ze (a physical foaming agent, a low-GWP environmentally friendly foaming agent) in a composite foaming system, the closed-cell rate of the material is strictly controlled at ≥92%, with an average pore size of 100-200μm, achieving optimal performance. The semi-closed-cell structure in this range has the best attenuation effect on low-frequency impact sound, while the closed-cell structure ensures excellent thermal insulation performance (thermal conductivity ≤0.035W / (m·K)).

[0016] A further optimization of the polyurethane foam sound insulation material for indoor floors described in this invention is as follows: The damping and sound-insulating modifier has a median particle size (D50) of 25 μm to 35 μm, a true density of 1.10 to 1.20 g / cm³, and a moisture content of no more than 0.5 wt%, exhibiting good flowability and dispersibility. Preferably, the bulk density of the damping and sound-insulating modifier is 0.60 to 0.70 g / cm³.

[0017] This specific structural design enables the damping and sound insulation modifier to be uniformly dispersed in the polyurethane matrix, solving the problem of poor compatibility between inorganic fillers and the polyurethane matrix, avoiding filler sedimentation and performance degradation due to long-term use, and improving material durability; and dissipating sound energy through the high damping characteristics of the butyl rubber shell, while the hollow glass microspheres in the core utilize their hollow structure and high hardness to generate micro-vibration damping and reflect sound waves under the action of sound waves, while significantly reducing the overall thermal conductivity of the material, thereby achieving a triple synergistic sound insulation and heat preservation effect of "damping energy dissipation, sound wave scattering, and enhanced thermal resistance".

[0018] A further optimization of the polyurethane foam sound insulation material for indoor floors described in this invention is as follows: The composite catalyst is a ternary system composed of a gel catalyst, a foaming catalyst, and a trimerizing catalyst in a mass ratio of 1-2:0.5-1:0.5-1. The ternary catalytic system precisely balances the foaming and gelation reactions, avoiding defects such as bubble collapse and closed-cell shrinkage, and improving the heat resistance of the material.

[0019] in, The gel catalyst is triethylenediamine, which regulates the rate of resin crosslinking reaction. The foaming catalyst is bis(2-dimethylaminoethyl) ether, which precisely controls the foaming reaction rate; The trimer catalyst is potassium isooctanoate, which promotes the trimerization reaction of isocyanate and improves the dimensional stability and heat resistance of the material.

[0020] A further optimization of the polyurethane foam sound insulation material for indoor floors described in this invention is as follows: The isocyanate index of the reaction between component A and component B is 1.25 to 1.4, so as to form a semi-interpenetrating network structure and balance the strength and toughness of the material.

[0021] A further optimization of the polyurethane foam sound insulation material for indoor floors described in this invention is as follows: The foam stabilizer is polyether-modified silicone oil.

[0022] A further optimization of the polyurethane foam sound insulation material for indoor floors described in this invention is as follows: The closed-cell rate of the polyurethane foam sound insulation material for indoor floors is ≥92%, the average pore size is 100~200μm, the weighted normalized impact sound pressure level L′nT,w≤64dB, the thermal conductivity is ≤0.035W / (m·K), and the compression performance is ≥300kPa.

[0023] The second objective of this invention is: A method for preparing the aforementioned polyurethane foam sound insulation material for indoor floors is provided, comprising the following preparation steps: Preparation of component S1.A: High-functionality rigid polyether polyol, long-chain flexible polyether polyol, and bio-based polyether polyol were dehydrated separately and then mixed in proportion to obtain a polyether polyol composition. The polyether polyol composition, crosslinking agent, and foam stabilizer were mixed and stirred evenly. A damping and sound insulation modifier was added and dispersed at high speed to obtain a pre-dispersed slurry. The pre-dispersed slurry was cooled to below 40°C, and then a composite foaming agent and a composite catalyst were added. After stirring evenly at low speed, the slurry was degassed under vacuum, filtered, and sealed with nitrogen gas to obtain component A. Preparation of component S2.B: Under nitrogen protection, polymethylene polyphenyl isocyanate was heated to 60°C, and dehydrated hydroxyl-terminated polybutadiene was slowly added dropwise. After the addition was complete, the temperature was raised to 75±5°C for prepolymerization. The NCO content of the reaction system was monitored. When the NCO content reached 28-32%, the reaction was terminated. After cooling, a polymerization inhibitor was added, and the mixture was filtered, sealed with nitrogen, and packaged to obtain component B. S3. The polyurethane foam sound insulation material for indoor flooring is prepared by mixing component A and component B in a certain proportion and reacting and foaming.

[0024] The third objective of this invention is: This paper provides an application of the aforementioned polyurethane foam sound insulation material for indoor floors in an indoor floating floor sound insulation and thermal insulation system: Mix components A and B in the specified proportions, and then foam the mixture onto the concrete slab substrate by spraying or pouring on-site to form a foamed layer with a thickness of 8-20mm. Finally, pour a fine aggregate concrete protective layer onto the foamed layer to form a floating floor slab sound insulation and heat insulation structure.

[0025] This invention addresses the core problems of existing polyurethane foam materials used for indoor flooring, including poor low-frequency impact sound insulation, difficulty in balancing mechanical and acoustic properties, and inability to simultaneously meet high green building standards. Through multi-component, multi-level synergistic innovation, a new polyurethane foam sound insulation material specifically designed for indoor flooring has been developed, boasting comprehensive performance far exceeding existing technologies. It not only overcomes the technical bottleneck of highly efficient low-frequency impact sound insulation (≤64dB) but also simultaneously achieves a "performance triangle" of high strength, excellent thermal insulation, and high environmental friendliness. It fully meets and exceeds the requirements of the three-star green building evaluation standard, providing an ideal material solution for the construction of high-end green buildings and tranquil living environments. Its main technical features and effects are as follows: (1) This invention creatively incorporates a core-shell structure damping sound insulation modifier (a powder of cross-linked butyl rubber coated with high-strength hollow glass microspheres) as a necessary component into the formulation. The butyl rubber in the shell layer, as a high-damping material, can efficiently attenuate the vibrational energy of impact sound waves; the high-strength hollow glass microspheres (SiO2+Al2O3) in the core layer effectively block the sound wave propagation path through multiple reflections and scattering, while the hollow glass microspheres significantly reduce the thermal conductivity. This core-shell structure not only perfectly solves the compatibility problem between inorganic fillers and the polyurethane matrix, preventing performance degradation, but also achieves a synergistic sound insulation and heat preservation effect of "primarily damping energy dissipation, supplemented by sound wave blocking and thermal resistance enhancement." This is the primary and key innovation of this invention in achieving excellent low-frequency sound insulation performance (L′nT,w≤64dB).

[0026] (2) By compounding high-functionality rigid polyether, long-chain flexible polyether and bio-based polyether in a specific ratio, a polyol matrix with high crosslinking density (ensuring ≥300kPa compression performance), high damping characteristics (enhancing sound insulation) and good environmental friendliness was constructed. The flexible chain segments and the damping layer of the core-shell filler work synergistically to further optimize the material's ability to dissipate low-frequency vibrations; the bio-based polyether reduces VOCs from the source, meeting the requirements of green building materials.

[0027] (3) A composite foaming system of deionized water and environmentally friendly HFO-1234ze is adopted. Through the synergy of chemical reaction and physical vaporization, the foaming material has the best attenuation effect on low-frequency impact sound, while the closed-cell structure ensures excellent thermal insulation performance.

[0028] (4) Hydroxyl-terminated polybutadiene-modified MDI prepolymer was used as component B, and flexible damping segments were pre-introduced into the molecular chain, echoing the flexible design in component A. Combined with the strict preparation process of the controllable prepolymerization reaction, the uniformity of the final product structure, storage stability and performance reproducibility were guaranteed from both the molecular and process levels, so that the excellent performance in the laboratory could be stably realized in industrial production. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Any simple improvements to the preparation method of this invention based on the inventive concept are within the scope of protection of this invention.

[0030] Example 1: Preparation of a polyurethane foam sound insulation material for indoor floors Preparation of component A (raw materials: parts by weight): 30 parts of high-functionality rigid polyether polyol (functionality 7, hydroxyl value 400 mg KOH / g), 40 parts of long-chain flexible polyether polyol (functionality 2, hydroxyl value 80 mg KOH / g), and 30 parts of bio-based polyether polyol (castor oil-based polyether, hydroxyl value 150 mg KOH / g) were distilled and dehydrated to a moisture content ≤0.05%. 4 parts of crosslinking agent (TMP:BHE-BPA=1:2); 3 parts of compound foaming agent (water:HFO-1234ze=1:4); 0.5 parts of composite catalyst (triethylenediamine: bis(2-dimethylaminoethyl) ether: potassium isooctanoate = 2:1:1); 2 parts foam stabilizer (polyether modified silicone oil); 15 parts of damping and sound insulation modifier; The damping and sound insulation modifier is a core-shell structured powder with high-strength hollow glass microspheres (SiO2+Al2O3) as the core and cross-linked butyl rubber as the shell; in the core-shell structure, the mass ratio of the core material to the shell material is 7:3, and the thickness of the shell layer is 9μm; (1) In a closed mixing vessel, three types of dehydrated polyether polyols were added to a closed mixing vessel equipped with a double planetary stirrer, high-speed dispersion, temperature control and vacuum system. The stirring was turned on at a low speed of 30 rpm. The crosslinking agent and foam stabilizer were added and stirred for 10 min to mix. The damping and sound insulation modifier was added and dispersed at a high speed of 800 rpm for 30 min to obtain a pre-dispersion slurry of homogeneous filler-polyether. The control index was: slurry fineness ≤50μm, no visible powder agglomeration, and no stratification. (2) Cool down to below 40℃ (35℃ in this example), add composite foaming agent and composite catalyst, stir at 50 rpm for 20 min; control the temperature not to exceed 45℃ throughout the process to avoid high-speed stirring causing the foaming agent to volatilize and the material to undergo prepolymerization reaction; (3) Vacuum degassing at -0.095MPa and 40℃ for 30 min to completely remove the air mixed in during the stirring process; after degassing, take a sample for central control testing, and obtain component A after passing the test; (4) Filter the qualified A component material through a 100-mesh sealed filter, fill the packaging with dry nitrogen to replace the air inside, seal the packaging, and store it in a cool, dry, and light-proof warehouse. The storage temperature should be controlled between 5 and 35°C. It is strictly forbidden to expose it to sunlight or contact it with water.

[0031] Component A is a homogeneous mixture of polyol matrix, functional additives, and sound insulation modifiers, which is the core carrier of product performance. This process solves the problems of filler agglomeration and unstable performance caused by one-time feeding in the existing process by step feeding and graded dispersion.

[0032] Polyurethane reactions are extremely sensitive to moisture. This section is fundamental to ensuring performance while avoiding the shortcomings of existing processes in terms of insufficient moisture control. All hydroxyl-containing raw materials (terpolymer polyether polyol composition, crosslinking agent, hydroxyl-terminated polybutadiene) are dehydrated for 2 hours at 105°C and -0.095MPa vacuum using a molecular distillation dehydration device before use. The moisture content is measured to be ≤0.05% and the materials are then sealed with nitrogen gas for later use.

[0033] Preparation of component B: (1) Add polymethylene polyphenyl isocyanate (NCO≈31%) into a nitrogen-protected reactor to replace the air and completely remove the air and moisture in the reactor; heat to 60°C and slowly add dehydrated (moisture ≤0.05%) hydroxyl-terminated polybutadiene (HTPB, molecular weight≈1500) dropwise over 30 min to avoid local overheating of the reaction; (2) Heat to 75±5℃ and keep the reaction at that temperature for 2 hours, during which time the NCO content is monitored; when the NCO content is stable in the range of 28-32%, immediately turn on the cooling water to terminate the reaction. (3) Cool to below 40°C, add 0.02% of the total material mass of the polymerization inhibitor tributyl phosphate, stir for 10 min to terminate the residual reaction, stabilize the product storage performance, and avoid viscosity increase during storage. (4) Quality Inspection and Packaging: Finished product sampling and control testing, the qualified indicators are: The NCO content is 28-32%, the viscosity at 25℃ is 300-500 mPa·s, and the hydrolyzed chlorine content is ≤0.05%. Qualified materials are filtered through a 100-mesh sealed filter, filled with dry nitrogen and sealed under positive pressure to obtain component B. Component B is stored in a cool, dry warehouse, isolated from moisture and air, and the storage temperature is controlled at 5-25℃. It is strictly forbidden to store it with active substances containing hydroxyl or amino groups.

[0034] By introducing damping flexible segments through a controlled prepolymerization reaction, the sound insulation performance and storage stability of the material are improved simultaneously, with the entire process controlled in an oxygen-free and water-free environment.

[0035] The polymethylene polyphenyl isocyanate is stored under nitrogen positive pressure in a sealed environment throughout the entire process, and is strictly prohibited from contact with air and moisture. Before use, the hydrolyzed chlorine content should be tested to be ≤0.05%, and the NCO content should meet the nominal value.

[0036] Preparation and properties of polyurethane foam sound insulation materials: Mix component A and component B at a mass ratio of 1:1.35, and inject the mixture into a 300mm×300mm×20mm mold using a high-pressure sprayer for foaming (ambient temperature 25℃, humidity 60%). Test performance after curing at room temperature for 7 days.

[0037] Comparative Example 1 A commercially available brand of 20mm thick polyurethane sound insulation foam board for floors.

[0038] Performance testing The results of the tests conducted according to the relevant national standards are shown in Table 1.

[0039] Table 1 Comparison of Performance Test Results

[0040] According to the results in Table 1, the material of the present invention is significantly superior to commercially available products in key aspects such as low-frequency sound insulation, thermal insulation, compression performance and stability, and its overall performance meets the high standards of green building.

[0041] Example 2: Application of Floating Floor System Clean the concrete substrate to a smooth surface (error ≤3mm / 2m) and ensure it is dry (moisture content ≤8%). Apply 50mm wide sound insulation and vibration damping strips to the base of the wall. Preheat components A and B to 22℃ before application. Using a high-pressure sprayer (13MPa), mix components A and B in a 1:1 ratio and spray continuously and evenly onto the substrate to form a 15mm thick foamed sound insulation layer (ambient temperature 20℃, humidity 70%). After 24 hours of curing, seal the site and allow it to fully cure in 7 days. Subsequently, pour a 40mm thick fine aggregate concrete protective layer with embedded wire mesh to form a complete floating floor system.

[0042] Test results: The weighted normalized impact sound pressure level improvement of the system meets the design requirements.

[0043] In summary, the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any changes, modifications, and evolutions made by those skilled in the art without departing from the scope of the present invention using the disclosed technical content are considered equivalent embodiments of the present invention. Furthermore, any changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention are within the protection scope of the present invention.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] Experimental methods not specified in this invention are generally performed under conventional conditions or as recommended by the manufacturer.

[0046] Unless otherwise stated, the various optimized technical solutions in this invention can be combined with each other.

[0047] Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0048] Experimental methods not specified in the instructions and examples are generally performed under standard conditions or as recommended by the manufacturer.

[0049] The various raw materials, reagents and components used in this invention are all commonly used raw materials in the field unless otherwise stated.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this invention.

Claims

1. A polyurethane foam sound insulation material for indoor flooring, characterized in that: It is prepared by reacting and foaming components A and B at a mass ratio of 1:1 to 1.5; Component A comprises the following raw material components in parts by weight: 100 parts of polyether polyol composition, 1-5 parts of crosslinking agent, 2-6 parts of composite foaming agent, 5-20 parts of damping and sound insulation modifier, 0.1-2 parts of composite catalyst, and 1-3 parts of foam stabilizer. The polyether polyol composition is a ternary compound system composed of high-functionality rigid polyether polyol, long-chain flexible polyether polyol, and bio-based polyether polyol in a mass ratio of 2-3:3-4:2-3; wherein... The high-functionality rigid polyether polyol has a functionality of 6-8 and a hydroxyl value of 350-450 mgKOH / g; The long-chain flexible polyether polyol has a functionality of 2-3 and a hydroxyl value of 50-100 mgKOH / g; The bio-based polyether polyol is castor oil-based or soybean oil-based polyether polyol with a functionality of 2-3 and a hydroxyl value of 100-200 mgKOH / g. The damping and sound insulation modifier is a core-shell structured powder with high-strength hollow glass microspheres as the core and cross-linked butyl rubber as the shell; in the core-shell structure, the mass ratio of the core material to the shell material is 7:3 to 6:4, and the thickness of the shell layer is 8μm to 15μm. Component B is a hydroxyl-terminated polybutadiene-modified polymethylene polyphenyl isocyanate prepolymer with an NCO content of 28-32%.

2. The polyurethane foam sound insulation material for indoor flooring according to claim 1, characterized in that: The crosslinking agent is a composite system composed of trimethylolpropane and bisphenol A dihydroxyethyl ether in a mass ratio of 0.5-1:1-2.

3. The polyurethane foam sound insulation material for indoor flooring according to claim 1, characterized in that: The composite foaming agent is a composite system composed of deionized water and HFO-1234ze in a mass ratio of 1:3 to 5.

4. The polyurethane foam sound insulation material for indoor flooring according to claim 1, characterized in that: The median particle size D50 of the damping and sound insulation modifier is 25μm to 35μm, the true density is 1.10 to 1.20 g / cm³, and the moisture content is not higher than 0.5 wt%.

5. The polyurethane foam sound insulation material for indoor flooring according to claim 1, characterized in that: The composite catalyst is a ternary system composed of a gel catalyst, a foaming catalyst, and a trimerizing catalyst in a mass ratio of 1-2:0.5-1:0.5-1; in, The gel catalyst is triethylenediamine; The foaming catalyst is bis(2-dimethylaminoethyl) ether; The trimerizing catalyst is potassium isooctanoate.

6. The polyurethane foam sound insulation material for indoor flooring according to claim 1, characterized in that: The isocyanate index of the reaction between component A and component B is 1.25 to 1.

4.

7. The polyurethane foam sound insulation material for indoor flooring according to claim 1, characterized in that: The foam stabilizer is polyether-modified silicone oil.

8. The polyurethane foam sound insulation material for indoor flooring according to claim 1, characterized in that: The closed-cell rate of the polyurethane foam sound insulation material for indoor floors is ≥92%, the average pore size is 100~200μm, the weighted normalized impact sound pressure level L′nT,w≤64dB, the thermal conductivity is ≤0.035W / (m·K), and the compression performance is ≥300kPa.

9. A method for preparing an indoor polyurethane foam sound insulation material for flooring according to any one of claims 1 to 8, characterized in that: The preparation steps include the following: Preparation of component S1.A: High-functionality rigid polyether polyol, long-chain flexible polyether polyol, and bio-based polyether polyol were dehydrated separately and then mixed in proportion to obtain a polyether polyol composition. The polyether polyol composition, crosslinking agent, and foam stabilizer were mixed and stirred evenly. A damping and sound insulation modifier was added and dispersed at high speed to obtain a pre-dispersed slurry. The pre-dispersed slurry was cooled to below 40°C, and then a composite foaming agent and a composite catalyst were added. After stirring evenly at low speed, the slurry was degassed under vacuum, filtered, and sealed with nitrogen gas to obtain component A. Preparation of component S2.B: Under nitrogen protection, polymethylene polyphenyl isocyanate was heated to 60°C, and dehydrated hydroxyl-terminated polybutadiene was slowly added dropwise. After the addition was complete, the temperature was raised to 75±5°C for prepolymerization. The NCO content of the reaction system was monitored. When the NCO content reached 28-32%, the reaction was terminated. After cooling, a polymerization inhibitor was added, and the mixture was filtered, sealed with nitrogen, and packaged to obtain component B. S3. The polyurethane foam sound insulation material for indoor flooring is prepared by mixing component A and component B in a certain proportion and reacting and foaming.

10. The application of the polyurethane foam sound insulation material for indoor floors as described in claim 1 in an indoor floating floor sound insulation and thermal insulation system, characterized in that: Mix components A and B in the specified proportions, and then foam the mixture onto the concrete slab substrate by spraying or pouring on-site to form a foamed layer with a thickness of 8-20mm. Finally, pour a fine aggregate concrete protective layer onto the foamed layer to form a floating floor slab sound insulation and heat insulation structure.

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